Currently, there are various kinds of balls available in the market, and balls with the most basic form are directly molded with rubber materials. To create different visual impression and touch of balls, to meet different requirements for use of balls, and to enable easy separation of one type of ball from others, the balls are usually provided on their surface covers with different recessed ribs or other surface textures. For example, a basketball has a plurality of grains and recessed ribs formed thereon; and a football is formed of a plurality of hexagonal leather covers to create a plurality of seams and grooves thereon. Generally speaking, most types of balls are air-inflated to get elasticity and the ability of bouncing.
Conventionally, a ball is inflated by compressing air into an inflatable inner bladder of the ball via an inflation valve installed on the ball. Please refer to FIG. 1. A conventional ball inflation valve 10 includes an air passage 11 partially extended into the inflatable inner bladder of a ball. The air passage 11 is provided at a center with an axially extended through hole 111 for communicating the inflatable inner bladder with air outside the ball. A locating portion 12 is radially outward extended from an outer surface of the air passage 11 for closely connecting to the inflatable inner bladder. The through hole 111 is normally in a closed state (not shown). To inflate the ball, an inflation needle is pierced through the through hole 111, so that an airway (not shown) is formed along the through hole 111.
The conventional ball inflation valve is usually made of a sulfide. Please refer to FIG. 2. When a surface cover 13 of the ball is in direct contact with the sulfide-made inflation valve 10, a yellowing smudge 14 will form in an area of the surface cover 13 adjoining the sulfide-made inflation valve 10. The yellowing smudge 14 will form even on a completely new ball and would have considerable influence on a consumer's desire for buying the ball. Therefore, it is necessary to improve the conventional ball inflation valve.